Purpose::
For some time it has been known that individuals with primaryglaucoma have increased sensitivity to glucocorticoids (GC).More recent techniques have allowed researchers to reveal awidespread expression of glucocorticoid receptors (GCRs) inthe eye, suggesting the important function GC have in ocularhealth. We have begun to study the presence of both the glucocorticoidreceptors and their prereceptors in the eyes of beagles withprimary-open angle glaucoma (POAG) and age-matched normals byimmuno-localization.

Results::
Within normal canine specimens, cells of the nonpigmented epithelium(NPE) of the CB processes stained weakly and diffusely for bothGCR and 11bHSD1 within their cytoplasm, being strongest in theadults. Among the glaucomatous dogs, the reaction for GCR and11bHSD1 in the NPE was considerably more intense and localizedthan the age-matched normals, especially among the Beagles withearlier stages of POAG and prior to IOP elevation. Within thenormal iridocorneal angle (ICA), the trabecular meshwork reactedpositively for GCR with little age-related differences. Withinthe eyes of the moderate and advanced POAG Beagles, GCR localizationwithin the ICA and adjacent region was greater than that ofage-matched normals. 11bHSD1 localization was not observed withinICAs of normal eyes but seen among affected animals, havingbeen most pronounced during moderate stages of the disease andintensely present within the corneal endothelium.

Conclusions::
Immuno-localization of both GCR and 11bHSD1 was successfullyobserved in both the normal and glaucomatous canine eye. Changesin the apparent activity of GCR and 11bHSD1 within the aqueoushumor outflow pathway of individuals with spontaneous glaucomaoccurred prior to disease expression and continued during itsprogression. The potential differential responsiveness of GCRsin this glaucomatous model may help to understand what roleGCs possess in the development of spontaneous glaucomas.